For example, Japanese Laid Open Patent Application No. 8-44643 discloses following matters. Namely, a client terminal connected with a LAN inside a company, a router which connects the LAN inside the company with an external network, a gateway device connected with the external network (e.g. whose URL (Uniform Resource Locator) is www.out.company.co.jp), and various servers (e.g. URL of one of the servers is www.is.university.ac.jp) exist, the client terminal acquires information on the various servers from the gateway device. If a HTML file acquired from other servers includes link information, the gateway device changes the link information. For example, if “http://www.is.university.ac.jp/welcome.html” is a link destination, the gateway device changes the link information to “http://www.out.company.co.jp/http://www.is.university.ac.jp/welcome.html”. Moreover, if on the LAN inside the company only HTTP (Hyper Text Transfer Protocol) can be used and link information represents the usage of FTP (File Transfer Protocol), for example, when a user selects such a link, the gateway device acquires information via FTP from another server, and converts the information into a hyper text format and sends the information in the hyper text format via HTTP to the client terminal.
In the conventional technique described above, client terminals connected with the LAN inside the company are limited, and a gateway device doesn't need to perform processes in consideration of the type of each client terminal and so on.
However, the type of device which can be connected to computer networks such as the Internet increased rapidly, so it is really difficult to prepare contents information for all the devices with the difference in the screen size or the number of digits and the type of supported markup language, or it costs very much.
On the other hand, users hope to use useful information, regardless of the type of device. Particularly on the cellular phone, available sites are limited for every communication careers, and even if very useful sites exist, users of other careers may not be able to see it on their cellular phones.